* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: #333;
}

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
    background: rgba(0, 51, 102, 0.9);
    color: white;
    z-index: 100;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: bold;
}

.nav-links a {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    margin: 0 0.5rem;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    background: rgba(255, 255, 255, 0.2);
}

.btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background: #ff6633;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    transition: transform 0.3s;
}

.btn:hover {
    transform: translateY(-2px);
}

footer {
    text-align: center;
    padding: 2rem;
    background: #003366;
    color: white;
}